Mixing cylinder or drum for concrete-mixers.



T. J. 00NWAY. MIXING CYLINDER. 0R DRUM FOR CONCRETE MIXERS.

APPLIGATION FILED AUG. 5, 1912.

Patented Mar. 25, 1913.

1N VEN TOR WITNESSES 7720mm? Janway ArroRNmY THOMAS J. CONWAY, OF OAKLAND, GALIFORNIA.

MIXING crnmnnn on. new ron consume-mans.

T 0 all whom it may concern Be it known that I, THOMAS J. CONWAY, a citizen of the United States, residing at Oakland, in the county of Alameda and State of California, have invented new and useful Improvements in Mixing Cylinders or Drums for Concrete-'Mi'xers, of which the following is a specification.

This invention relates -to cylinders. for concrete mixers or like machines, and in particular to that type known as continuous mixersi The object of the invention is to divide the body of material passing through the mixer into smaller, separate portions to produce a more thorough mixing of the mate rial than has heretofore been accomplished A further object of this invention is generally to improve this class of machinery so as to increase their utility, durability and efiiciency.

The inventlon consists in providing the cylinder properwith a suitable number of spiral tubes, through which the material to be mixed is fed, and in providing means whereby water may be introduced into the tubes at the proper point to give the best results. I

It also comprises details of construction which will be more fully explained by reference to the accompanying drawings, in

Figure lis a side elevation. Fig. 2 is a longitudinal sect-ion of the exterior shell showing the tubes in elevation. Fig. 3 is work .3, and may be revolved at a suitable speed by the gears 4 and 5. Thecylinder may also be provided with a feed hopper 6, through which the materialis fed to the cylinder, and a discharge chute or hopper 7. Within the cylinder is mounted a suitable number of spiral tubes 8, preferably circular in cross section, as shown in Fig. 3. These are carried and suitably secured at their ends in heads 9 and 10 which entirely close the intervening spaces, as 11, between Specification of Letters Patent.

Application filed August 5, 1912. Serial No. 713,277.

tubes 8.

Patented Mar.2 5,1913.

the ends of the tubes to prevent the entrance of material into the s aces between the tubes; the heads being esigned to. entirely close the ends of the cylinder and are only perforated to receive the ends of the spiral 12 indicates a water pipe cylinder which extends a suitable distance into the-cylinder where it is connected by the radial pipes 13 with the spiral tubes8. The other end of the pipe is connected with a universal union 14, or like device, and is carried the Y provided with a valve 15 by which the water fed to the spiral tubes is controlled.

In operation, the materials to be mixed are dumped into the receiving hopper 6, from whence the mixture enters the spiral tubes 8 when these are in their lower position. By feeding the'material through the separate spiral tubes better results are obtained, for the reason that-the material is divided into separate, small portions which are constantly being turned and mixed while passing through the spiral tubes. Another advantage which adds to the efficiency of the mixer is the result produced by two different mixing actions which willbe described, as follows: First, the material is mixed by rolling over and over on itself during the revolution of the cylinder. Second, an end over end mixing action takes place while passing through the spiral tube which is caused by the material constantly rolling down the inclined surface of the spiral tube, as indicated by the arrow a. It can plainly be seen that material picked up by the spiral tubes at the lower portion of the feed hopper will, when" carried up to the position shown by the arrow a in Fig. 2, turn over-itself and roll down the steep incline of the spiral. This rolling action being in a direction at right angles to the first rolling action described produces an end over end motion of the material. Another advantage gained by the employment of the spiral tubes is that they eliminate the necessity of mounting the cylinder in an inclined position. The material always rolling down the incline of the spiral as the cylinder revolves will insure a positive feed of the material through the tube. The chief advantage gained by mounting the cylinders in a horizontal position is the elimination of thrust bearings and'like devices usually employed where the cylinder is mounted in an inclined position. However, when it is water may be introduced at any point along the cylinder; the amount being adjusted to a nicety by the valve 15.

While this invention has proven itself,

particularly adapted for use in concrete mixers, I wish it understood that I do not wish to limit myself to this specific use, as I have found that it has proven very practical and efiicient when used for drying pur- I poses, as drying sand in connection with asphalt work. When using it for drying purposes it is only necessary to disconnect the radial pipes 13 and admit steam or hot air through the pipe into the space between the spiral tubes.

Having thus described my invention, what I claim and desire to secure by Letters Patent is 1. A mixing cylinder comprising a cylinder and a series of spiral tubes within the cylinder, means for conducting material to the spiral tubes, and means or revolving the cylinder.

2. In a concrete mixer, the combination of a cylinder having closed ends and a series of internal inclosed spiral conductors, said conductors having open ends exposed through the ends of the cylinder, means for revolving the cylinder and means for feeding material to be mixed, into said conductors.

3; In a concretemixer, the. combination of a cylinder having heads closing the ends thereof, said ends provided with perforat-ions, a series of independent spirally arranged conductors within the cylinder and having their ends entering the perforations in said heads, means for revolving the cylinder, and means for feeding material to be mixed into the ends of said conductors.

4. In a concrete mixer, a cylinder, a series of spiral tubes within said cylinder, means for feeding the materials to be 'mixed into the spiral tubes, means for conducting water into the spiral tubes, said means comprising a pipe mounted within the cylinder and con nected by radial pipes to the spiral tubes, and means for revolving the cylinder.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

THOMAS J. CONWAY. Witnesses J. E. LUDWIG, ELLA L. SMITH. 

